Portable Mobile Radio (HAM or GMRS) Set - Power Box Build

[NT2C]

Picked up a 12v 20Ah LiFePO4 battery for under $50 during the last hours of Prime Days.  I'm planning to use it to build a ruggedized 12v radio power source in an ammo can that I can use to power the dual-band digital radio that I took out of my truck before I sent it to Chimpski.  Combined was a magnetic antenna to stick on the ammo can this will give a simple field portable rig that's got a lot more power than an HT and is more versatile.

[Mr. E. Monkey]

Picked up a 12v 20Ah LiFePO4 battery for under $50 during the last hours of Prime Days.  I'm planning to use it to build a ruggedized 12v radio power source in an ammo can that I can use to power the dual-band digital radio that I took out of my truck before I sent it to Chimpski.  Combined was a magnetic antenna to stick on the ammo can this will give a simple field portable rig that's got a lot more power than an HT and is more versatile.

I would love to learn more about this setup!  

[NT2C]

I'll post pictures when it's complete.

[Mr. E. Monkey]

I'll post pictures when it's complete.

Sweet.  It's one of those fields that all I know is that I don't know anything close to enough about it.  

Are you planning to use multiple cans, or get something like a 40mm ammo can to keep everything in one ready-to-go unit?  I can wait for pics, but the gears are turning.  

[NT2C]

I'll post pictures when it's complete.

Sweet.  It's one of those fields that all I know is that I don't know anything close to enough about it. 

Are you planning to use multiple cans, or get something like a 40mm ammo can to keep everything in one ready-to-go unit?  I can wait for pics, but the gears are turning.   

Current plan is to put the battery and charger for it in a .50 cal can and the radio in an LAPG Zombie Hunter bag (yes, I'm trying to get them to send us some) along with the disassembled antenna and cables.  The two together will comprise the kit.

[Mr. E. Monkey]

Nice!  That does sound like it would have more flexibility in how you set it up that way.  I think I was visualizing trying to fit everything into a single hard container, which would probably cause more problems than it would solve.  Having it in a bag like that would probably improve mobility, too, over trying to lug a bigger can around.

[NT2C]

So, the ammo can is going to be one of my brand new M2A1 cans that I bought for just a few bucks back when Norma ammo had a surplus of them.  The battery fits nicely under the lid (which will have a rubber lining) but takes up a little more than half the width, so I can't fit in two. 

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This also means I can't use that space for the first charger I bought as it's the same width as the battery.  I've located a different charger though, one that's a dedicated LiFePO4 charger with just a red/green LED (which simplifies things), that will fit perfectly.  It will be attached to a small platform made from 1/2" Sch 40 PVC that serves three functions: holding the charger; holding the battery in place; and providing a storage area under the platform for the charger power cord.

I'm waiting on my next SS check to continue with the new charger purchase and the PVC and fittings purchase.

Power out is still being considered but as I want to keep the watertight integrity of the can intact (because water and lithium and electricity get along so well together) I've decided against anything that penetrates the can, leaving just having to fabricate a fold-down panel that will also hold the can lid up, probably with a pair of Powerpole connections and maybe a small LED voltage readout.

[Mr. E. Monkey]

Power out is still being considered but as I want to keep the watertight integrity of the can intact (because water and lithium and electricity get along so well together) I've decided against anything that penetrates the can, leaving just having to fabricate a fold-down panel that will also hold the can lid up, probably with a pair of Powerpole connections and maybe a small LED voltage readout.

As nice as a power out port/plug setup sounds, keeping water out sounds even better.    I wonder if something like this:  Amazon.com: Nilight 2 Pack Car Cigarette Lighter Socket DC 12V Waterproof Power Outlet Adapter Replacement with Terminals Wires and Screws for Marine Boat Motorcycle, Boat, Car,Truck, RV, ATV : Cell Phones & Accessories
Amazon.com: Nilight 2 Pack Car Cigarette Lighter Socket DC 12V Waterproof Power Outlet Adapter Replacement with Terminals Wires and Screws for Marine Boat Motorcycle, Boat, Car,Truck, RV, ATV : Cell Phones & Accessories  
would work (not sure what plug type you would be using), but it might be better to have the can open, especially when you're charging.  I know some chargers can put out some decent heat, and keeping that sealed up might not be great.

That is a bummer that you can't fit two batteries, or the original charger...but a smaller charger, with the framework to secure the charger and cable does sound like a good trade-off, honestly.  I was wondering if a PA108 can, measuring  11-3/4″ x 6-3/4″ x 8-1/4",  instead of  11″ x 5.5″ x 7", would give you enough room, but then again, would it be worth the extra weight?

Really, having the battery and a smaller charger in the M2A1 can sounds like the best balance between weight, size, and function.  

Seriously, don't mind me.  I'm sure you've thought through all of this, and besides, I overthink things to a failing point anyway, I think.  KISS, monkey, KISS.  

[NT2C]

Power out is still being considered but as I want to keep the watertight integrity of the can intact (because water and lithium and electricity get along so well together) I've decided against anything that penetrates the can, leaving just having to fabricate a fold-down panel that will also hold the can lid up, probably with a pair of Powerpole connections and maybe a small LED voltage readout.

As nice as a power out port/plug setup sounds, keeping water out sounds even better.    I wonder if something like this:  Amazon.com: Nilight 2 Pack Car Cigarette Lighter Socket DC 12V Waterproof Power Outlet Adapter Replacement with Terminals Wires and Screws for Marine Boat Motorcycle, Boat, Car,Truck, RV, ATV : Cell Phones & Accessories
Amazon.com: Nilight 2 Pack Car Cigarette Lighter Socket DC 12V Waterproof Power Outlet Adapter Replacement with Terminals Wires and Screws for Marine Boat Motorcycle, Boat, Car,Truck, RV, ATV : Cell Phones & Accessories 
would work (not sure what plug type you would be using), but it might be better to have the can open, especially when you're charging.  I know some chargers can put out some decent heat, and keeping that sealed up might not be great.

That is a bummer that you can't fit two batteries, or the original charger...but a smaller charger, with the framework to secure the charger and cable does sound like a good trade-off, honestly.  I was wondering if a PA108 can, measuring  11-3/4″ x 6-3/4″ x 8-1/4",  instead of  11″ x 5.5″ x 7", would give you enough room, but then again, would it be worth the extra weight?

Really, having the battery and a smaller charger in the M2A1 can sounds like the best balance between weight, size, and function. 

Seriously, don't mind me.  I'm sure you've thought through all of this, and besides, I overthink things to a failing point anyway, I think.  KISS, monkey, KISS.   

The outputs will likely be one of these from Powerwerx:



or


Mounted on a hinge that will be attached to the front inside of the case with an epoxy like JB Weld and with the positions filled with an array of Anderson powerpole plugs, battery monitor gauges, a on/off switch/breaker, and maybe a USB C PD port.







Hinged so that in the up position they lock to and hold open the lid.

[Beowolf]

As Monkey mentions, you've surely thought through the options, but if you need a bigger can, I have a small variety.

[Mr. E. Monkey]

That hinged setup for the ports is a great idea.  I might have hinted at it before, but this is a really neat idea, and I am looking forward to seeing how it turns out.  

[MacWa77ace]

Should you put some sort of shock absorbing insulation on the bottom and sides of the battery that touch the metal? something like small squares of closed cell foam glued on. Or maybe those silicon cabinet door bumpers. Or maybe a plastic 'bracket' that you can glue in to keep it off the bottom and sides, and then maybe even be able to 'clamp' the battery in place so it doesn't jostle around.

I heard an 'urban legend' once that says never set a batter directly on concrete as it drains it. And I set a battery on concrete that was relatively new and fully charged and maybe 6 months later it was dead and unchargeable.  I don't know if it just died or if it died 'cause of the concrete floor. So I am extrapolating that to the metal. And what happens if you set the can on concrete?

[NT2C]

Should you put some sort of shock absorbing insulation on the bottom and sides of the battery that touch the metal? something like small squares of closed cell foam glued on. Or maybe those silicon cabinet door bumpers. Or maybe a plastic 'bracket' that you can glue in to keep it off the bottom and sides, and then maybe even be able to 'clamp' the battery in place so it doesn't jostle around.

I heard an 'urban legend' once that says never set a batter directly on concrete as it drains it. And I set a battery on concrete that was relatively new and fully charged and maybe 6 months later it was dead and unchargeable.  I don't know if it just died or if it died 'cause of the concrete floor. So I am extrapolating that to the metal. And what happens if you set the can on concrete?

Battery cases are incredibly tough on their own.  Having one inside a steel shell is not going to materially change that and I can think of no reason such padding would be useful.  However, if it makes you feel better to have something there, the plan was always to add some clear, double-sided gel tape (Alien Tape brand) to the bottom of the battery to help anchor it.  You should also note what I've previously said about a rubber lining on the inside of the can lid and a PVC framework that will hold the battery in place.

The semi-myth about car batteries on concrete does not apply to any battery made in the last half-century when plastic cases started being the norm.  When batteries were made with hard rubber cases yes, there was a reason never to leave the battery on the ground or on concrete because the hard rubber was somewhat porus and water seeping into the rubber would allow weak current flow that quickly drained the less powerful batteries of the era.  Plastic battery cases don't have this problem. Automotive batteries do naturally self-discharge, so one being dead after six months is pretty normal.

[MacWa77ace]

Automotive batteries do naturally self-discharge, so one being dead after six months is pretty normal.

Tell that to the people in Hollywood writing these Zombie Apocalypse movies. replace a dead battery with a 5 year old battery from another car and voila.

Gas and batteries don't last long enough to get that car started and for those 10 year plus car finds. the rubber on the tire will be rotted.

[Mr. E. Monkey]

Automotive batteries do naturally self-discharge, so one being dead after six months is pretty normal.

Tell that to the people in Hollywood writing these Zombie Apocalypse movies. replace a dead battery with a 5 year old battery from another car and voila.

Gas and batteries don't last long enough to get that car started and for those 10 year plus car finds. the rubber on the tire will be rotted.

Heck, I'd be happy with one of those 20 round revolvers they have, or a rifle with a 300 round magazine.

...then again, they tend to have lousy penetration, so maybe not.